The dwarven rings

[Attalus]

Originally Posted by Gordis

That's why I call it a common mistake. Reading "tower" as "power" is simply a tweak - no one has the right to do this with canonic text. Mordor had never been occupied by Numenor, nor was its power or tower broken. After the Downfall, Sauron simply returned home.

Barad-Dur was destroyed except for its foundations, Gandalf says. I take this to mean that Sauron rebuilt the aboveground portions of the Dark Tower but not the underground portions, which perhaps contained the dungeons and some magical areas?